Field of the Invention
The present invention relates to a transducer unit, an acoustic probe including the transducer unit, and a photoacoustic apparatus including the acoustic probe.
Description of the Related Art
A measurement system has been proposed in which a subject is irradiated with light, an acoustic wave (typically, an ultrasonic wave, but referred to as a photoacoustic wave in the present specification) is generated from a measurement object in the subject on the basis of a photoacoustic effect, and the generated acoustic wave is received by using a hemispheric ultrasonic probe (U.S. Patent Application Publication No. 2011/0306865, hereinafter referred to as Patent Document 1). The hemispheric ultrasonic probe is constituted by a plurality of ultrasonic transducer elements arranged on a hemispheric surface.
Descriptions will be given with reference to FIG. 23. FIG. 23 illustrates a subject 10, a light source 11, an ultrasonic probe 12, an ultrasonic transducer 13, light beam 21, a photoacoustic wave 22, and a medium 30 (acoustic matching material). The ultrasonic probe 12 has a shape of hemisphere and is provided with a plurality of ultrasonic transducers 13 and the light source 11. The subject 10 is arranged so as to be partially surrounded by the hemisphere of the ultrasonic probe 12, and the medium 30 is filled between the subject 10 and the ultrasonic probe 12. The light source 11 emits the light beam 21 to the subject 10, and the photoacoustic wave 22 generated in the subject is received by the plurality of ultrasonic transducers 13 included in the ultrasonic probe 12 to perform imaging of the subject.
At this time, when the number of ultrasonic transducers arranged on the hemispheric surface of the supporting member is increased, it is possible to improve an image quality of an image of the subject. To increase the number of ultrasonic transducers, the plurality of ultrasonic transducers need to be arranged so as to be in proximity to one another on the hemispheric surface. However, an optimal configuration for arranging the ultrasonic transducers in proximity to one another has not been proposed up to now.